Volkswagen plans to launch in January a recall of vehicles with software at the center of the emissions-rigging scandal and aims to fix them all by the end of next year, the company's new chief executive says.

Volkswagen has said up to 11 million vehicles worldwide across several of its brands contain the diesel engine with the software used to cheat on U.S. emissions tests. CEO Matthias Mueller told the daily Frankfurter Allgemeine Zeitung: "It will hopefully be fewer, but in any case still far too many."

Asked when the recall will begin, Mueller said in an interview published Wednesday that "care goes before speed."

"If everything goes as planned, we can start the recall in January," he said. "All the cars should be in order by the end of 2016."

Mueller said the company will have to fix the EA 189 diesel engine "in combination with various transmissions and country-specific designs. So we don't need three solutions, but thousands."

A software update will suffice to fix the problem in most cases, but some vehicles could need new injectors and catalyzers, Mueller was quoted as saying. He said the automaker may need to set up temporary specialist workshops to deal with the more complex cases.

Mueller said that "according to current information, a few developers interfered in the engine management." He said he doesn't think the management board made the decision to use the manipulated software.

Volkswagen said after news of the scandal emerged last month that it had suspended some employees, but didn't give details. Mueller said that four have been suspended so far — among them three senior managers who at various times were responsible for engine development at Volkswagen. He didn't identify them.

He added, without elaborating, that others have already retired.

Volkswagen so far has set aside 6.5 billion euros ($7.3 billion) to cover the cost of recalls and other efforts to win back customers' trust. Asked if that will be enough, Mueller didn't say yes or no.

He said in Wednesday's interview, when asked if VW will give up its luxury Phaeton sedan and its Bugatti brand, that the company will "have to look at the value contributed by every model and every individual brand."